I'm trying to figure out the best way to deal with this with my 2012 M3. The Pioneer X6500BT unit I put in my old car was flawless (e.g., zero sync issues with videos and no delayed responsiveness with play/pause/etc.); I expect this to be the same, but it has an approximately 2.7 second delay. I just shot off emails to both Mazda and Johnson Controls (the maker of the BT module) to see what they say. Probably won't get anywhere (seems no one else has), but I'm either going to find a device for which the delay isn't present and figure out why, or give up on that and figure out how to wire in a new head unit while keeping the factory mic and upper LCD cluster intact and functional. If I don't get too frustrated and just give up on everything, I'll post an update when I have it.